Bone tumours: an approach to the focal bone lesion

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Advanced

Finding a lump or hole in a bone on an X-ray can be alarming, but most focal lesions are benign, and many are incidental. The plain radiograph remains the best single test for characterising a bone lesion, because it shows how the bone has responded over time. The aim is to answer two questions: does this look aggressive or non-aggressive?, and what is the likely diagnosis given the patient's age and the lesion's location? A short, fixed approach answers both. This page teaches that approach, the classic lesions, the "don't touch" lesions that should be left alone, and the referral rules for suspected sarcoma.

1. A seven-step approach

1. Age. The single most useful fact. Over about 40, a destructive lesion is a metastasis or myeloma until proven otherwise. Under about 20, think of osteosarcoma, Ewing sarcoma, bone cysts, non-ossifying fibroma and osteochondroma.
2. Location. Which bone, and where in it: epiphysis (chondroblastoma when the physis is open; giant cell tumour after it closes; infection), metaphysis (most primary tumours) or diaphysis (Ewing sarcoma, myeloma, fibrous dysplasia). Is it central, eccentric or in the cortex?
3. Margin and zone of transition (below).
4. Periosteal reaction (below).
5. Matrix: what, if anything, the lesion produces (below).
6. Soft-tissue mass: its presence suggests an aggressive process.
7. Number: single or multiple. Multiple lesions suggest metastases, myeloma, multiple enchondromas, fibrous dysplasia or Langerhans cell histiocytosis.

Always look for a previous film. A lesion unchanged for years is very likely benign.

2. Margins and the zone of transition

The zone of transition is the border between the lesion and normal bone. It reflects how fast the lesion is growing, and it is the most reliable single sign of aggressiveness. Lodwick's work underpins the patterns below.

Pattern	Appearance	Implication
Geographic, sclerotic rim	A sharp, narrow border with a white rim.	Slow growth; usually non-aggressive.
Geographic, no sclerotic rim	Sharp border, no rim.	Intermediate; for example giant cell tumour or myeloma.
Moth-eaten	Multiple small, ragged holes that merge.	Aggressive.
Permeative	Innumerable tiny holes with no definable edge; the most aggressive pattern.	Aggressive: Ewing sarcoma, lymphoma, myeloma, infection, metastasis.

3. Periosteal reaction and matrix

Periosteal reaction

Pattern	Meaning	Examples
Solid, smooth, thick	Slow process; the periosteum has had time to lay down solid bone.	Healing fracture, osteoid osteoma.
Lamellated ("onion-skin")	Intermittent growth.	Ewing sarcoma, osteomyelitis.
Spiculated "sunburst"	Rapid growth with spicules radiating outwards.	Osteosarcoma.
"Hair-on-end"	Perpendicular spicules.	Ewing sarcoma; also thalassaemia in the skull.
Codman triangle	Periosteum lifted at the edge of the lesion forms a triangle of new bone.	Aggressive lesions: osteosarcoma, Ewing sarcoma, also infection.

Matrix

• Osteoid (bone-forming): fluffy, cloud-like density, as in osteosarcoma.
• Chondroid (cartilage-forming): "rings and arcs" or popcorn calcification, as in enchondroma and chondrosarcoma.
• Ground glass: a hazy, uniform density, typical of fibrous dysplasia.
• None: purely lytic lesions such as cysts, giant cell tumour or most metastases.

4. High-yield lesions

Lesion	Typical age	Site	Key X-ray features
Osteosarcoma	10–25 (second peak in older adults, with Paget disease or after radiotherapy)	Metaphysis around the knee; proximal humerus	Mixed lytic and sclerotic, osteoid matrix, sunburst reaction, Codman triangle, soft-tissue mass.
Ewing sarcoma	5–20	Diaphysis or metadiaphysis of long bones; pelvis; ribs	Permeative destruction, onion-skin reaction, large soft-tissue mass. Fever and raised inflammatory markers can mimic infection.
Chondrosarcoma	Over 40	Pelvis, proximal femur, shoulder girdle	Chondroid matrix; deep endosteal scalloping (more than two-thirds of cortical thickness), cortical breach or a soft-tissue mass favour it over enchondroma. Pain is a warning sign.
Giant cell tumour	20–40 (physis closed)	Epiphysis extending to subchondral bone: knee, distal radius	Eccentric, lytic, expansile; narrow zone of transition but no sclerotic rim. Locally aggressive.
Simple bone cyst	5–15	Central metaphysis of proximal humerus or femur	Central, lucent, mildly expansile, thin sclerotic rim; fallen fragment sign after fracture.
Aneurysmal bone cyst	10–20	Eccentric metaphysis; posterior elements of the spine	Expansile, "blown-out", thin shell; fluid–fluid levels on CT or MRI.
Non-ossifying fibroma	10–20	Eccentric, cortically based metaphysis around the knee	Lucent, multiloculated, with a scalloped sclerotic margin. Heals with sclerosis.
Osteochondroma	10–20	Metaphysis around the knee, proximal humerus	Bony outgrowth with continuity of cortex and medulla with the parent bone, pointing away from the joint. Malignant change is rare; a cartilage cap over about 1.5 cm in an adult, growth after skeletal maturity or new pain needs review.
Enchondroma	20–50	Hands (the commonest phalangeal tumour), humerus, femur	Central lucency with chondroid calcification; may present with a pathological fracture in a finger.
Osteoid osteoma	10–30	Cortex of femur and tibia; posterior elements of the spine	Small lucent nidus (under about 1.5–2 cm) with dense surrounding sclerosis. Night pain relieved by NSAIDs. CT shows the nidus.
Fibrous dysplasia	5–30	Femur ("shepherd's crook"), ribs, skull	Ground-glass matrix, expansion, sclerotic rind.
Langerhans cell histiocytosis	Under 10	Skull, spine, long bones	Punched-out skull lesion with bevelled edges; vertebra plana. Can look aggressive.

5. "Don't touch" lesions

Some lesions are so characteristic that they need no biopsy; biopsy can even mislead, because their histology may resemble a malignancy. Recognising them saves patients from unnecessary procedures:

• Non-ossifying fibroma and fibrous cortical defect.
• Bone island (enostosis): a dense focus with spiculated, "brush-like" margins.
• Cortical desmoid at the back of the distal femoral metaphysis.
• Healing fracture and myositis ossificans, which matures from the outside in (zonal ossification).
• Degenerative subchondral cysts next to an osteoarthritic joint.
• Avulsion injuries, which can look destructive while healing.
• A benign-appearing enchondroma in the hand.

6. Metastases and myeloma

Metastases

Metastases are the most common malignant bone lesions in adults. They favour red marrow: the spine, pelvis, ribs, skull and proximal femur and humerus.

• Lytic: lung, kidney and thyroid (renal and thyroid metastases are often expansile), breast, melanoma.
• Sclerotic: prostate (the commonest in men), breast, carcinoid, bladder.
• Mixed: breast, lung.
• On an AP spine film, a destroyed pedicle gives the "winking owl" sign.
• Watch for pathological fractures through lesions in long bones; scoring systems such as Mirels' estimate the risk of an impending fracture.

Multiple myeloma

• Multiple punched-out lytic lesions without a sclerotic rim, classically in the skull ("raindrop skull"), with diffuse osteopenia and vertebral collapse.
• Lesions are often cold on a bone scan. NICE NG35 recommends whole-body imaging (low-dose CT or MRI) rather than relying on a skeletal survey.
• A plasmacytoma is a solitary expansile lytic lesion.

Paget disease, another cause of bone enlargement and sclerosis in older adults, is covered in metabolic bone disease.

7. Pitfalls and mimics

• Infection mimics tumour: osteomyelitis can produce permeative destruction and lamellated periosteal reaction, like Ewing sarcoma.
• Stress fractures produce periosteal new bone and sclerosis that can look worrying, especially early.
• A normal X-ray does not exclude a marrow tumour. Myeloma, lymphoma and metastases can replace marrow before the bone changes; MRI is far more sensitive.
• Anatomical variants such as the pseudotumour of the humerus (the greater tuberosity in older people) and nutrient canals.
• Calling a lesion benign in an adult over 40 without considering metastasis or myeloma.

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	The seven-step approach, aggressive versus non-aggressive features, and the age rule for metastases and myeloma.
Nurse / practitioner	Night pain and a bone mass in a young person are red flags; know the urgent referral pathway.
Junior doctor	Describe the lesion systematically, compare with old films, and refer aggressive lesions urgently rather than biopsying or reassuring.
Radiographer	Two orthogonal views including the whole lesion and the nearest joint; flag aggressive appearances through your preliminary comment process.
Advanced / FRCR	Lesion-specific differentials, chondrosarcoma versus enchondroma, myeloma imaging pathways and don't-touch lesions.

Practise on bone and joint X-rays →

References

1. Miller TT. Bone tumors and tumorlike conditions: analysis with conventional radiography. Radiology 2008;246(3):662–674. pubs.rsna.org
2. National Institute for Health and Care Excellence. Suspected cancer: recognition and referral (NG12). nice.org.uk
3. National Institute for Health and Care Excellence. Myeloma: diagnosis and management (NG35). nice.org.uk
4. Lodwick GS, et al. Determining growth rates of focal lesions of bone from radiographs. Radiology 1980;134(3):577–583.
5. Radiopaedia. Paget disease of bone. radiopaedia.org

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.